The present invention relates to a portable engine-operated working machine such as a portable engine-operated electric generator.
The frame structure for portable engine-operated working machines is disclosed in Japanese Laid-Open Utility Model Publication No. 53-3302. The disclosed frame structure includes a main frame shaped as a rectangular thin continous frame and two support members disposed in spaced relation on the slender bottom of the main frame. The engine-operated working unit is fixedly positioned on the support members. Two front and rear cover halves are coupled to the main frame on its opposite sides.
In the above conventional design, a fuel tank is attached by a bracket secured to the inner surfaces of laterally spaced vertical bars of the main frame. Since the main frame is in the form of a continuous loop, it is necessary to insert the fuel tank longitudinally and fasten the flange around the fuel tank to the brackets. In view of the low structural accuracy of the tank and the low attachment accuracy of the brackets, the fuel tank cannot easily and accurately be installed. Since the bracket is attached transversely of the main frame and the frame is covered by the two front and rear cover halves, the fuel tank is required to be fastened to the bracket to facilitate detachment of the cover halves. Therefore, the number of steps required to assemble the components together is increased. Other fuel tanks of general design also cannot be attached with ease. Where the engineoperated electric generator is portable, it has a carrying handle on top thereof. For assembly, after the engine and the generator have been assembled in position, the bracket is attached, and then the fuel tank is placed and fastened thereto, followed by attachment of the carrying handle over the fuel tank. Consequently, the assembling process involves many steps, and has a poor efficiency.
The present invention has been made in an effort to solve the above problems.